P0B3D: The first battery block has a direct low-signal check

P0B3D monitors the low end of block-one voltage sensing in this GM battery controller. The failure quantity is a block-one indication below 2V. The code concerns the sensing result and does not prove that the physical block has discharged to that value.

This row checks block one directly

The source lists block one alone in the low-limit condition. Some subsequent channels in the same document use a pair of adjacent block readings, but that additional condition is not present here. Do not copy a neighboring channel's logic into P0B3D.

The controller must be in run mode, with its low-voltage supply in range and P0A1F inactive. Failure uses 15 qualifying samples out of 20 at 100ms intervals. A single low display value is not the whole sample decision.

Keep circuit evidence separate from battery health

Capture block-one voltage, controller supply and any related P0B3C or pack-voltage faults. The rationality code compares measurements differently and cannot simply be substituted for this low-limit result.

The document supplies no physical block location, open-wire test or battery replacement verdict. Those require the correct sensor map and diagnostic procedure. A trained high-voltage technician must establish safe access using approved isolation and verification. Never treat a low scan reading as confirmation that the battery or its sensing conductors are de-energized.

Source and applicability

GM 2010 10OBDG10 Hybrid Diagnostics, only the cited controller and monitor. These are historical calibration examples; individual vehicle, engine and hardware applicability is not established. GM PDF, page 222.